cm:Concept: us-gaap:UndistributedEarningsDiluted
| Undistributed Earnings, Diluted |
| us-gaap:UndistributedEarningsDiluted |
| The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed. Includes the adjustments resulting from the assumption that dilutive securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:UndistributedEarningsDiluted |